Concrete is widely used because it is local, available, cost effective (cheap), inert, durable, versatile in mix, form and finish and has excellent in-use performance across many parameters. All of these contribute to concrete’s sustainability value.
Designers and constructors have a role in maximising the sustainability advantages of concrete and in minimizing the adverse impacts of concrete through design. There are also impacts in manufacturing concrete and its constituents as with all materials and products. These are explained elsewhere on this website together with the initiatives – past, present and future – by the industry to minimise environmental and social impacts.
Concrete, and constituents to make it, are locally sourced. There is not reliance on trans global movement of raw materials or concrete itself thereby minimising transport impacts. Local sourcing also maximises the scope for good responsible sourcing (responsible sourcing covers environmental and social impacts of construction products.)
Sustainable construction seeks to use all virgin materials responsibly with consideration of future generations – this is more easily achieved for materials that are abundant and available as is the case for concrete. Good governance ensures responsible access to resources and the restoration of quarries at end of life.
- Cost Effective
To deliver the needs of society in a cost effective manner is part of sustainability. This is particularly true for emerging economies for which key sustainability goals include health, education and housing.
- Inert and Durable
Concrete is inert so it does not rust, rot or burn and it can be used in water supply systems and healthy buildings to deliver high water and air quality.
Typically, long lasting projects are economically, environmentally and socially sustainable and often rely on concrete because of its durability. Sustainable benefits of drinking water and healthy buildings are self evident.
- Versatile in Mix, Form and Finish
Mix: The range of concrete mixes is limitless. Together with different manufacturing methods, the resulting concretes can have a wide range of engineering properties such as density (3 to 30kN/m3) and compressive strengths up to 200MPa. This versatility means that use of material can be optimised according to the end-use requirements.
Form: The versatile form also means designers can find an optimum for their project: The range is very wide whether it be factory made – small concrete bricks, 30m long bridge beams, decorative cladding – or cast insitu – safety barriers, tunnel linings, structural frames and floors with cast in voids to save material/weight. With such versatility, optimisation is possible against a range of parameters to deliver the sustainable outcome required.
Finish: Concrete can be cast with a range of surface textures and colours. Along with inherent fire resistance, this can minimise or eliminate the need for less durable floor, wall and ceiling coverings. These coverings can have a significant environmental impact especially if replacement rates are taken into account.
- In-use Performance
See in-use performance table below.
Designers and constructors have a role to play
Their roles include:
- Ensuring optimum specification of concrete mix given desired function
- Utilising the versatility of form
- Maximising efficiency of design and structural material utilisation
- More than just structure – using thermal mass, minimising finishes
The inherent performance properties of concrete mean designers can deliver sustainable projects
|Fire Resistance||Concrete does not burn. Therefore it reduces both the waste of materials and the noxious emissions caused by fire.||The fire resilience of concrete reduces damage and limits the potential loss of livelihood or homes as a result of fire. During construction, the concrete frame presents no fire risk to neighbours.||Regulations require the safe evacuation of occupants but do not ensure the survival of property. Concrete structures comply with life safety regulation but can also resist fire to enable cost-effective repair and reuse.|
|Durability||Due to the long life of all concrete structures, material impacts on the environment are kept to an absolute minimum.||The durability of concrete structures means that, once built, they are rarely out of use for maintenance and hence cause minimum social disruption.||Concrete is a very stable and durable material with an extremely long life. As a result, maintenance costs are extremely low for concrete structures.|
|Acoustic Performance||Concrete has good acoustic performance and there is less reliance on finishes and materials which have a short lifespan. Hence less material is used and potential waste is avoided.||Concrete’s mass absorbs sound, ensuring quality of life, particularly in high density living, where noise from neighbours can be a major issue.||Concrete walls and floors provide the required acoustic separation with minimum finishes, and therefore minimal costs and maintenance.|
|Robustness/Security||Concrete structures are robust, reducing the risk of damage to finishes. Therefore, less material is used throughout a structure’s lifecycle.||Solid concrete masonry and party walls provide safe, secure buildings. Prevention of intruders helps to build safer communities.||Concrete structures, particularly those with minimal finishes, will suffer less damage and cost less to repair and maintain.|
|Flood resilience||Concrete retains its structural integrity, resulting in minimal waste of materials following a flood event.||Concrete and masonry structures can be designed to resist water penetration, keeping inconvenience and disruption to business, homeowners and the community to a minimum.||Downtime of businesses, homes and essential community services is minimised if flooded buildings have been constructed in concrete.|
|Thermal Mass||Concrete’s thermal mass allows it to be used to reduce buildings’ heating and cooling energy load, thus reducing operational carbon.||The thermal mass inherent in concrete provides a simple and effective means to reduce overheating for those who do not have air conditioning. Overheating is a growing health and wellbeing issue, particularly among the elderly.||Using the thermal mass of concrete will lower running costs of a building. It will also reduce the plant needed on site, leading to lower operating and maintenance costs.|
Header photo by Paul Mocan on Unsplash